As per the Wikipedia article for Thor (2011):
Thor is a 2011 American superhero film based on the comic book character of the same name published by Marvel Comics. It is the fourth film released as part of the Marvel Cinematic Universe. The film was directed by Kenneth Branagh, written by Ashley Edward Miller, Zack Stentz and Don Payne, and stars Chris Hemsworth, Natalie Portman, Tom Hiddleston, Stellan Skarsgård, Colm Feore, Ray Stevenson, Idris Elba, Kat Dennings, Rene Russo and Anthony Hopkins. The film tells the story of Thor, the crown prince of Asgard, who is exiled from his homeland to Earth. While there, he forms a relationship with Jane Foster, a scientist. However, Thor must stop his adopted brother Loki, who intends to become the new king of Asgard.